The Thermal Stability and Magnetic Properties of Exchange-Coupled Trilayers
- 주제(키워드) Thermal stability , Exchange-coupled trilayers , Magnetic Random Access Memory
- 발행기관 고려대학교 대학원
- 지도교수 임상호
- 발행년도 2011
- 학위수여년월 2011. 2
- 학위구분 석사
- 학과 일반대학원 신소재공학과
- 원문페이지 55 p
- 실제URI http://www.dcollection.net/handler/korea/000000025346
- 본문언어 영어
- 제출원본 000045640945
초록/요약
Magnetic properties and thermal stability of nanostructured exchange-coupled trilayer(TR) are studied by analytical/numerical combined method. The magnetization switching properties of magnetic cells containing defects are investigated by using micromagnetic simulation. Switching behaviors are observed in the relatively large cell sizes; the single layer (SL) cells showing vortices switch incoherently, but TR cells switch coherently, even though the thickness asymmetry of the TR is quite large. At a small cell, suitable for high density magnetic random access memory (MRAM), however, the switching occurs coherently in both the SL and TR cells. The relative strength of the interlayer dipole fields in comparison to that of the interlayer exchange coupling is examined in nanostructured TR cells as functions of their size, shape, and thickness. The relative strength increases with decreasing cell size and with increasing cell thickness, in agreement with the size and thickness dependence of the magnetostatic interactions. The thermal stability factor in nanostructured cells of ferromagnetically or antiferromagnetically coupled TRs is calculated by an analytical/numerical method. The method is then critically tested by comparing the calculated results with reliable experimental results reported recently in the literature [S. Yakata, H. Kubota, T. Sugano, T. Seki, K. Yakushiji, A.Fukushima, S. Yuasa, and K. Ando, Appl. Phys. Lett. 95, 242504 (2009)]. For a ferromagnetically coupled trilayer (TRFM), the comparison indicates a very weak interlayer exchange coupling between the two magnetic layers where the magnetization switching occurs in the via AP mode.
more목차
Abstract 1
List of figure captions 3
List of table captions 7
Chap. 1 Introduction 8
Chap. 2 Magnetic properties
2. 1 Switching behaviors of SLs and TRs 12
2. 1. 1 Model and Calculation 12
2. 1. 2 Results and Discussion 16
2. 2 Relative strength of Interlayer exchange
coupling and interlayer dipole fields 28
2. 2. 1 Model and Calculation 28
2. 2. 2 Results and Discussion 33
Chap. 3 Thermal stability
3. 1 Model and Calculation 38
3. 2 Results and Discussion 43
Chap. 4 Conclusions 48
Chap. 5 References 51
